The drowning deaths of two fishermen have prompted the Deputy Coroner to recommend crew aboard commercial fishing boats wear life jackets which can inflate automatically.

Adam Nicolai and Justin Hellyer died when a fishing boat sank off Stansbury on Yorke Peninsula in September 2008.

The men had been fishing with their friend and skipper of the boat, Andrew Pisani, when two big waves swamped the vessel during a squall.

The court was told the men were not wearing life jackets and all three tried to swim to safety but only Mr Pisani survived.

Deputy Coroner Anthony Schapel said the boat was unregistered and would not have been regarded as seaworthy for the conditions.

"I have accepted Mr Pisani's evidence that the effect of the two large waves was so swift and catastrophic that there was simply no time for any person on board to don PFDs (personal flotation devices) or to secure the buoyancy rings," he said.

"Nevertheless it is hard to disagree with the conclusion of the Industrial Court that there had been a foolhardy and reckless approach to the wearing of life jackets at night in offshore waters in a small vessel that was prone to sinking if swamped.

"As a matter of common sense, the wearing of PFDs would significantly have increased the possibility of both men surviving. Without them they had little chance of survival once a decision had been made not to try to make shore with Mr Pisani."

The coroner recommended the Transport Minister make it a legal requirement for self-inflating flotation devices to be worn at all times by crews on commercial boats.

Mr Pisani's company previously was fined in the Industrial Court.

Coronial recommendations

That measures be introduced requiring owners and operators of vessels of the kind with which this inquest is concerned to report to Department of Planning, Transport and Infrastructure material alterations to the equipment of those vessels; That measures be introduced requiring owners and operators ... to have such a vessel surveyed or otherwise inspected for seaworthiness; That the Minister for Transport consider making it a legal requirement that each occupant of a vessel of this type, while being used for commercial purposes, at all times wear a personal flotation device that is designed to inflate automatically on immersion.The operator of the vessel should be under an obligation to ensure that all occupants of the vessel are wearing such devices.